From 22e63b1f1bf689d3b19a0de2e5217aca3a2cfff9 Mon Sep 17 00:00:00 2001
From: Chris Lew <clew@codeaurora.org>
Date: Tue, 11 Dec 2018 18:55:52 -0800
Subject: [PATCH] net: qrtr: Add support for DEL_PROC control message

Add the DEL_PROC control message for forwarding usecases. If this proc
acts as a gateway between two procs then they need a notification to
clean up servers and client ports when either goes down. This message
acts as notification to clean up all resources associated with the node
in the message.

Change-Id: I3514f54aa0221e104196e2120e929cc9f351847d
Signed-off-by: Chris Lew <clew@codeaurora.org>
---
 include/uapi/linux/qrtr.h |  7 +++++
 net/qrtr/qrtr.c           | 57 +++++++++++++++++++++++++++++++++++++++
 net/qrtr/qrtr.h           |  2 ++
 3 files changed, 66 insertions(+)

diff --git a/include/uapi/linux/qrtr.h b/include/uapi/linux/qrtr.h
index f7e2fb3d752b..ad3b401f1e2e 100644
--- a/include/uapi/linux/qrtr.h
+++ b/include/uapi/linux/qrtr.h
@@ -27,6 +27,8 @@ enum qrtr_pkt_type {
 	QRTR_TYPE_NEW_LOOKUP	= 10,
 	QRTR_TYPE_DEL_LOOKUP	= 11,
 };
+#define QRTR_TYPE_DEL_PROC	13
+
 
 struct qrtr_ctrl_pkt {
 	__le32 cmd;
@@ -43,6 +45,11 @@ struct qrtr_ctrl_pkt {
 			__le32 node;
 			__le32 port;
 		} client;
+
+		struct {
+			__le32 rsvd;
+			__le32 node;
+		} proc;
 	};
 } __packed;
 
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 4b39d0a70231..87d5f7523e6d 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -838,6 +838,60 @@ static void qrtr_notify_bye(u32 nid)
 	qrtr_local_enqueue(NULL, skb, QRTR_TYPE_BYE, &src, &dst, 0);
 }
 
+static u32 qrtr_calc_checksum(struct qrtr_ctrl_pkt *pkt)
+{
+	u32 checksum = 0;
+	u32 mask = 0xffff;
+	u16 upper_nb;
+	u16 lower_nb;
+	u32 *msg;
+	int i;
+
+	if (!pkt)
+		return checksum;
+	msg = (u32 *)pkt;
+
+	for (i = 0; i < sizeof(*pkt) / sizeof(*msg); i++) {
+		lower_nb = *msg & mask;
+		upper_nb = (*msg >> 16) & mask;
+		checksum += (upper_nb + lower_nb);
+		msg++;
+	}
+	while (checksum > 0xffff)
+		checksum = (checksum & mask) + ((checksum >> 16) & mask);
+
+	checksum = ~checksum & mask;
+
+	return checksum;
+}
+
+static void qrtr_fwd_del_proc(struct qrtr_node *src, unsigned int nid)
+{
+	struct sockaddr_qrtr from = {AF_QIPCRTR, 0, QRTR_PORT_CTRL};
+	struct sockaddr_qrtr to = {AF_QIPCRTR, 0, QRTR_PORT_CTRL};
+	struct qrtr_ctrl_pkt *pkt;
+	struct qrtr_node *dst;
+	struct sk_buff *skb;
+
+	list_for_each_entry(dst, &qrtr_all_epts, item) {
+		if (!qrtr_must_forward(src, dst, QRTR_TYPE_DEL_PROC))
+			continue;
+
+		skb = qrtr_alloc_ctrl_packet(&pkt);
+		if (!skb)
+			return;
+
+		pkt->cmd = cpu_to_le32(QRTR_TYPE_DEL_PROC);
+		pkt->proc.rsvd = QRTR_DEL_PROC_MAGIC;
+		pkt->proc.node = cpu_to_le32(nid);
+		pkt->proc.rsvd = cpu_to_le32(qrtr_calc_checksum(pkt));
+
+		from.sq_node = src->nid;
+		to.sq_node = dst->nid;
+		qrtr_node_enqueue(dst, skb, QRTR_TYPE_DEL_PROC, &from, &to, 0);
+	}
+}
+
 /**
  * qrtr_endpoint_unregister - unregister endpoint
  * @ep: endpoint to unregister
@@ -861,7 +915,10 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
 			continue;
 
 		spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
+
 		qrtr_notify_bye(iter.index);
+		qrtr_fwd_del_proc(node, iter.index);
+
 		spin_lock_irqsave(&qrtr_nodes_lock, flags);
 	}
 	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
diff --git a/net/qrtr/qrtr.h b/net/qrtr/qrtr.h
index fc6dcb368419..b80a14918c87 100644
--- a/net/qrtr/qrtr.h
+++ b/net/qrtr/qrtr.h
@@ -10,6 +10,8 @@ struct sk_buff;
 #define QRTR_EP_NID_AUTO (-1)
 #define QRTR_EP_NET_ID_AUTO (1)
 
+#define QRTR_DEL_PROC_MAGIC	0xe111
+
 /**
  * struct qrtr_endpoint - endpoint handle
  * @xmit: Callback for outgoing packets